Locomotive



1,4;54'931 R. F. HALL LOCOMOTIVE Filed Jan. 15, 1923 s Sheets-Sheet R. F. HALL LOCOMOTIVE} Filed Jan. 15. 1,923 3' SHeets-Sheet 3 ,yrlnlllll 'WIINEEQSES @MMW R. F. HALL Aug. 14,1923

LOCOMQTIVE Filed Jan. 15.

1923 3- Sheets-Sheet 5 of Schenectady,

tady and State of. New York, have invented Patented Aug. 14, 1923.

ROBERT F. HALL, OF SCHENEC'IADY, YQRK.

LOCOMOTIVE.

Application filed January 13, 1923. Serial No. 612,406,

To all whom it my concern:

Be it known that I, ROBERT F. HALL, a

citizen of the United States, and a resident in the county of Scheneca certain new and useful Improvement in Locomotives, of which improvement the following is a specification.-

y invention relates to locomotive engines of the type on which, through the intermediation of a cranked driving axle, more than two main or operatin steam cylinders are installed, as in those nown as threecylinder and four-cylinder engine The object of my invention is to enable increased economyin the consumption of steam, in locomotives of the types referred to, to be effected, without unduly increasing the di-' ameter' ofthe inside cylinder and the size and weight of the members connected therewith, the strength of which is a function of their diameters. A secondary object of my invention is to enable'a reduction of the diameter of the inside cylinder to be effected, when a relatively longer maximum cut off is operated, for the .purpose of limiting the size and weight of the parts.

The improvement claimed is hereinafter fully set forth. i c

In the accompanying drawings: Figure 1 is a diagrammatic side view, in elevation, of a three cylinder locomotive engine, embodying my invention; Fig. 2, a similar plan view of the same, showing the main, connecting rods of all three cylinders as coupled to the same driving axle; Fig. 3, a similar view, showing the mainrods of the inside and the outside cylinders as connected to different driving axles; Fig. 4, a front view, in elevation, showing all three cylinders as "of equal diameters; Fig. 5, a similar View, showing the two outside cylinders as of greater diameter than the central cylinder; Fig. 6, a vertical longitudinal central section through a cylinder and its "distribution valve chest; Figs. 7 and 8, ideal indicator diagrams illustrating, respectively, steam as cut oit at 50 per cent and at 85 per cent of the stroke of the piston; Fig. 9, a diagram showing the ordinarily preferred angular relation of the three cranks of a three cylinder locomotive; Fig. 10, an ideal turning moment diagram for a two cylinder engine with 85 per cent cut off; Fig. 11, a similar diagram for a three cylinder engine with 85 per cent cut off in all three cylinders;

cylinder type,

Fi 12, a similar diagram for a three cylin er engine, with 50 per cent in all three cylinders, the central cylinder being of smaller diameter than the outside cylinders; and, Fig. 13, a similar diagram for a three cylinder engine, with 85 per cent out off inthe central cylinder and 50 per cent cut oil in the outside cylinders, thecentral. cylinder being of smaller diameter than the outside cylinders and than the central cylinder referred to in the diagram Fig. 12-.

Locomotive engines of the ordinary two have been designed, and are now operating satisfactorily in. regular service. in which, for the purpose of efiecting a greater ratio of expansion, while the engine is exerting its maximum tractive force,the maximum cut oil has been caused to be made at, or not lgreater than, 50 per cent of the piston stro e. The result of this limitation of the period of steam admission has been the effecting of more wcik, or unit weight of steam used, as compared with common practice, in which the maximum out 01f is about 85 per cent of the piston stroke. By the term maximum cut elf is meant the greatest proportion of the piston stroke at which the admission of steam to the cylinders is permitted to be cut 05 by the distribution valve mechanism,

and from which point the workdone by the stean'i, in movmg the pistons, is that due to its expansion in the cylinders. As shown by the indicator diagrams, Figs. 7 and 8, the points of cutoff, in the two diagrams, are a and I), respectively, which points are located at 50 per cent and 85 per cent, respectively, of the piston stroke, 0. The areas of the diagrams are, as is well known in practice, proportionate to the net work done by the steam, during one stroke of the piston, corresponding to a half revolution of the crank pin, through 180 degrees.

The positions of a piston and its steam distribution yalve, at the point of 50 per cent maximum cut oil', are shown in Fig. 6, the piston-1, being at the middle of its stroke,"that is, having moved 50'per cent of its stroke in the cylinder, 1, and the dis- 'tributicn valve, 2, which is of the inside and and of itself, part of my throughout diagrams,

The valve operating mechanism by which the distribution valve is actuated, being well known in practice, and not forming, in resent invention, is not herein exemplified. The mean effective pressure, which is the average net pressure acting on one side '01 the piston, its stroke, is proportionate to the area of the indicator diagram, divided by its length, and is, approximately, per ,cent of the initial )ressure, in the case of an 85 per cent cut 0 and '70 per cent in the case of a 50 per cent cut 0 In-the operation of locomotives of the three cylinder and four cylinder types, having one or two inside cylinders the piston or pistons ofwhich is or are connected to a crank or cranks, on a driving axle, the turning moment is more uniform than that of the ordinary two cylinder locomo -tives, and it is therefore possible to obtain a greater exertion of power, relatively to adhesive weight, than'in the two cylinder type. The term turning moment will be understood -as meaning the product of the net force acting on the piston, at any given point of itsstroke, multiplied by the length or the crank in its corresponding angular position, pro ected on a vertical. line It will be seen, by reference to the turning moment Figs. 10 to 13, inclusive, that as the number of cylinders is increased, their combined turning moment becomes more uniform and the fluctuation between minimum and maximum power is reduced. nasmuch as the work performed during a, stroke varies directly as the, mean effective pressure, it follows'that, other things being equal, it'is necessary to increase the piston area acted upon by this pressure, to approximately 21 per cent, to obtain equal power, when a 50 per cent maximum out o is adopted instead of an 85 per cent, or other wiscuto increase the stroke in the same proportions, maintaining the same diameter, which would correspond to an increase of diameter of approximately 10 per cent.

Figs. lO'to 13 inclusive are ideal turning moment diagrams, Fig. 10 being illustrative ofthat in. a two cylinder engine. with 85 per cent maximum cut oil'; Fig. 11, that ion three cylinder engine, with 85 per cent main imu-m cut oil in all three cylinders; Fig. 12, that in a. three cylinder-engine, with 50 per cent maximum out o in all three cylinders, the'central cylinder being of smaller diameter than. the two outside cylinders; and, Fig.13, that in a three cylinder engine, with 85- per' cent maximum 'cut off in the central cylinder, and 50 per cent maximum cut oft in the two outside cylinders, the central cylinder being of smaller diameter than the two outside cylinders and than the central cylinder of Fig. 12. Ordinates in these diagrams will be proportionate to the combined the two cylinder engine,

--to provide -ferred to, is the attainment of.

' ditions impose a turning moment. of all the cylinders and horizontal distances proportional to the angular position of tance representing onecomplete revolution, or 360 degrees change in angular position.

The more uniform turning moment in the three cylinder engine, will be apparent from these diagrams, and it will also be noted that while the turning moment indicated in Fig. 12, isn'ot as uniform as that in Fig. 11, and shows greater mum and minimum, there is, nevertheless, a much lower range of fluctuation between maximuni and minimum than in the case of Fig. 10. known as the factor of adhesion, which is obtained by dividing the adhesive weight of the locomotive, by its tra'ctive force, is approximately t to 4.5 in two cylinder engines, and in some cases, where the boiler power is larger, in proportion to that of the cylinders, this factor may reach the value of 5 or more. The value of the fa'ctor'of adhesion is an ap proximate measure oi the relation between the capacities of the boiler and the cylintiers and, as this factor may, in some cases, be as low-as 3, will be seen that the boiler capacity of type of engine is a materially important consideration.- If the cylinders of an engine of such type be made of sufficient capacity to utilize a greater proportion of the adhesive weight of the locomotive, it is difiicult boiler capacity sufiicient for the supply of three cylinders, and, while economy in the use of steam is of prime importance in anyv type of locomotive, it is particularly desirable in the case of three and tour cylinder engines for this reason.

' My invention is based upon, and is the result of, an extended consideration of the .operative conditions and practical requirements hereinbefore explained, in locomotive engines of the types to which it relates, and its leading and characteristic;feature consists in a novel dispositiomhereinafter explained, of the relative capacities'of the inside and outside cylinders, whereby a comparatively short maximum cut olt may be operated, with the-result of developing the maximum boiler capacity and trac'tive force of the locomotive, withan economical consumption of steam, ameter of the inside cylinder and its connectedjmembers; A further result, of substantial importance, of the disposition rea total higher cylinder power thanwould be possible in the case where al threecylinders are of equal capacity, in which case structural conlimitation u on the inor stroke 0 The relation crease of diameter cylinder.-

In the practice otmy invention, referring on three cylinder engines, 1t this the cranks, the total disfluctuation between maxiand with-a minimum d the middle city than'wouldbe required in the case where ders, 1-,1","the central cylinder, 1, is ma descriptively to the specific embodiment thereof which is-herein exemplified, as aplied in a three cylinder single expansion ocomotive of the Mountain type, having alcentralcylihder, '1, and two outside 0 lin- (lie of greater capacity than would' be, if operated with a maximum cut oil of say, 85 per cent, required in the case where the three cylin ders are of equal diameters, but of less capathe three cylinders are of equal diameters and operated with a maximum cut oil of,

say, 50 per cent. In order to compensate for such reduction of capacity of the central' cylinder, the outside cylinders are made of greater capacity than would be necessary if all three cylinders were of equal diameters and operated with a maximum cut oil of, say, 50 per cent. For example, let there be considered a three cylinder engine, all the cylinders of which are of equal capacities, as in present practice, and as indicated by being shown of equal diameters in Fig. 4, as, say 24 inches, the valve gears being adapted to effect a maximum cut oil in full gear, of 85 per cent. Three cylinders, ofap goximately 26% inches in diameter, won (1 necessary in order to develop equal power with a maximum cut off of 50 er cent. By making the central cylinder mches in diameter, and the. two side cylinders each 27 inches in diameter, the same power can be developed, in full gear, with maximum cut off bf ,per cent in all three cylinders.

The pistons, 1, of all the cylinders, are, as 'in ,ordina practice, coupled by main connecting ro 1, to the crank pin of a crank,

9',-on a main driving axle, 9, either directly, as shown in Fig. 2, or through the intermediction of side or eouplin rods, 10, as shown in Fig. 3. Steam is supp led from the boiler, 11, to the distribution valve chests, 2", through which it is admitted to, and exhausted from, the cylinders, by the distribulition valves, 2. Various'tygs of valve gear,

by which said valves may operated to ef fact the out 01f desired, are well known in standard practice, and not, in and of themselves,,forming part of any presentinvention,-cre not herein exemplified. Fig. 9 indicates the crank pins of the three cylinders as set-in the symmetrical angular relation of 120 degrees apart, but while such location is ordinarily the preferred one, it may, in some cases, be found advisable to vary it in practice, and it is not an essential of my inventioli.

A still further reduction in the diameter of the central cylinder, and in the dimen sions and weight of its allied members, may

' be-efl'ected by adjusting the valve gears so as to effect a longer cut oil, as, say, 85 per cent,

in the central cylinder, and a shorter maximum cut ofi, as, say, 50 per cent, in the outcylinders 26% inches in diameter, The same power. would then, be obtained as in the operation of three cylinders, all of approximately 26% inches in diameter, with a maxi mum cut olf of 50per cent, as in the instance before referred to.

A reduction in, the diameter of thecentral cylinder may also be effected by increasing the stroke of its piston, relative y to that of the pistons of the outside cylinders. The decrease of the diameter of the entral cylindcr bein in the same proportion as the increase 0% piston stroke, a uniform cut oil may 'be operated in all three cylinders. However, inasmuch as the result of change of length of stroke varies as the first power, while that of change of diameter variesfa's the square, a change in diameter will, for this reason be found preferable. It will be obvious that other variations of point of cut oil; stroke of piston; and relative cylinder dimensions, may be-made without departure from the-spirit and operative principle of my invention.

In the operation of twov cylinder locomotives in which the maximum cut off is structurally limited to 50 per cent, there are four crank pin positions in each revolution from which the engine will not start, when steam is initiallya mitted to the cylinders from the boiler. This objection is overcome b the provision of what is termed a trici c port through which a small amount of steam is admitted before the distribution valve has reached its normal admission port. This .device ensures the starting of the engine from any crank pin osition, and while necessary in a two cylin er engineflt is, to a certain extent, objectionable, and it is not required in three or four cylinder engines.

I claim as my invention and desire to secure by Letters Patent:

1. In a single expansion locomotive, the combination of a cranked driving axle; a central cylinder; and two outside cylinders, the pistons of all of which cylinders being coupled to said drivin axle, and the capacity of the central cylinder being less than that of either of the outside cylinders.

2. In a single expansion locomotive, the combination of a cranked driving axle; a central cylinder; and two outside cylinders, the pistons of all of which cylinders being coupled to said driving axle, and the diameter of the central cylinder being less than that of either of the outside cylinders.

3. In a single expansion locomotive, the combination of a cranked driving axle; a central cylinder, two outside cylinders, the pistons of all of which cylindersbeing coupied to said-driving axle, and the diameter for effecting a comparatively short Iniximum cut off, as not exceeding 50 per cent, in said cylinders.

4. In a single expansion locomotive, the combination of a cranked driving axle; a central cylinder; two outside cylinders, the pistons of all of which cylinders being coupled to saiddrivingaxle, and the diameter of the central cylinder'being less than that of either of the outside cylinders; means for effecting a comparatively short maximum cut oil, as not exceeding 50 per cent, in the outside cylinders; and means for effecting a substantially longer maximum cut off in the central cylinder. I ROBERT F. HALL. Y

Witnesses:

J. SNOWDEN BELL,

W. WARNER. 

